a) Field of the Invention
This invention relates to an air conditioner duct suitable for connection with an air conditioner arranged in a vehicle such as a hydraulic excavator.
b) Description of the Related Art
FIG. 11 is a fragmentary longitudinal cross-sectional view showing a conventional air conditioner duct suitable for connection with an air conditioner arranged in a cab of a heavy machinery. The air conditioner duct according to the prior art illustrated in FIG. 11 can be arranged, for example, in a cab of a hydraulic excavator. The air conditioner duct, which is designated at numeral 50 in FIG. 11, is fixed on an unillustrated air conditioner for a cab (not shown). The air conditioner is arranged, for example, in a lower part at the rear of an operator's seat. The duct 50 downwardly terminates in an unillustrated lower horizontal extension. This lower horizontal extension is arranged extending along a floor of the cab and is fixed at an end portion thereof to an air outlet of the air conditioner. The unillustrated lower horizontal extension is upwardly bent, for example, at the front of the unillustrated operator's seat so that a vertical extension 51 is formed as shown in FIG. 11. Further, at a predetermined height, for example, at a height corresponding to the face of the operator seated in the operator's seat, the vertical extension is bent toward the face of the operator seated in the operator's seat, thereby forming an upper horizontal extension 52 as depicted in FIG. 11. An air outlet member 53 is integrally formed at a free end of the upper horizontal extension 52.
As is illustrated in FIG. 11, the air outlet member 53 has a vertical face 54, which forms a release portion for air guided thereto through the duct 50 as indicated by arrows 57, and is internally provided with a plurality of turnable fins 55 disposed at vertical intervals and also with means for interlocking these fins 55 so that the fins 55 have the same inclination, namely, a connecting rod 56. The fins 55 are arranged with one end portions thereof facing the vertical face 55 and opposite end portions thereof turnably connected with the connecting rod 56. Further, manipulation of an unillustrated knob, which is arranged in front of the vertical face 54 and is connected to some of the fins 55, makes it possible to move the connecting rod 56 in the vertical direction. In addition, as is depicted in FIG. 11, the above-mentioned fins 55 have the same shape and dimensions, and are basically arranged in a horizontal direction which is in parallel with the upper horizontal extension 52 of the duct 50.
When the fins 55 are held in horizontal positions as shown in FIG. 11, air which has been treated in the unillustrated air conditioner is guided through the duct 50 and, as is indicated by the arrows 57, is allowed to flow through the upper horizontal extension 57 and then along upper and lower surfaces, in other words, guide surfaces of the fins 55. This air is thereafter released in a Substantially horizontal direction into the cab through an opening in the vertical face 54 so that at the same flow rate as that of the air passing through the spaces between the individual fins 55, the air is caused to flow toward the face of the operator seated in the unillustrated operator's seat. Manipulation of the unillustrated knob makes it possible to direct via the connecting rod 56 the individual fins 55 at substantially the same inclination relative to a horizontal plane so that the direction of the air from the vertical face 54 can be changed to an obliquely upper direction or an obliquely lower direction.
Since the air outlet member 53 is integrally fixed to the free end of the upper horizontal extension 52 of the duct 50 in the conventional art constructed as described above, the direction of air blown out from the air outlet member 53 can be changed only to such an extent as controllable by the fins 55. If the duct 50 is installed based on the average physique of operators who are expected to sit in the operator's seat, an operator whose physique is greater or smaller than the average physique may not feel comfortable because air may not be fed at a sufficient flow rate to the face or the like of the operator.
If the duct 50 is installed from the standpoint of feeding air to the fact of the operator in the operator's seat as mentioned above, it would then become impossible to feed defrosting or demisting air, for example, against a front window located on a side of a front wall of the cab and in front of the operator and against a side window located on a side of a side wall of the cab. For these defrosting and demisting purposes, an additional measure is needed such as arrangement of additional ducts.
If the duct 50 is installed so that air is blown, for example, toward the front window located on the side of the front wall of the cab from the standpoint of defrosting and demisting of the window, the side window located adjacent the front window is not fed with sufficient air, resulting in the potential problem that defrosting or demisting of the side window may not be performed effectively. In such a case, certain additional means is needed for the side window.
As is apparent from the foregoing, the conventional art is accompanied by the problem that an area in which air can be fed at a sufficient flow rate is narrow and an object to which air can be fed is hence limited to a rather specific one.